Conservation agriculture

Conservation agriculture, as defined by the United Nations’ Food and Agriculture organisation (FAO), is “a farming system that promotes maintenance of a permanent soil cover, minimum soil disturbance, and diversification of plant species. It enhances biodiversity and natural biological processes above and below the ground surface, which contribute to increased water and nutrient use efficiency and to improved and sustained crop production”. The IPCC special report “Climate Change and Land” (2019) includes conservation agriculture among the incremental adaptation options to address climate risks. The three main principles of conservation agriculture (minimum soil disturbance, crop diversification, and permanent soil cover) help to protect the environment and to reduce both the impacts of climate change on agricultural systems (adaptation) and the contribution of the agricultural practices to greenhouse gases (GHG) emissions (mitigation) through sustainable land management. These principles, described in more details below, contribute to protect the soil from erosion and degradation, improve soil quality and biodiversity, preserve the natural resources and increase their use efficiency, while optimizing crop yields.

More in details, “minimum soil disturbance” is characterized by reduced tillage practices (such as ploughing, harrowing, and all the tillage operations ordinarily applied to prepare the soil for seed germination, seedling establishment and crop growth and production) through direct seeding and/or direct fertilizer placement. It helps to improve soil properties, preserve and increase soil organic matter, and hence reduce soil erosion. Moreover, no tillage and minimum tillage reduce energy consumption by agriculture machinery, enhance soil drainage, improve food supplies for insects, birds, and small mammals due to higher availability of crop residues and weed seeds in the soil. Indeed, a number of ecosystem services are provided by the minimum soil disturbance, including: water regulation, carbon storage, soil stability, protection of surface soils from erosion, enhanced water infiltration, increased soil fertility through enhanced nitrogen stocks (in the long term), improved soil, water, and air quality, reduction of soil erosion and fuel use. All these elements are of the highest importance in order to reduce the vulnerability of the agricultural systems and increase their adaptation capacity to climate change, contributing also to the mitigation objectives.

“Crop diversification” is the practice of cultivating more than one species in a given agricultural area, in the form of crop rotation and/or association. The diversification in cultivated species increases the adaptation capacity of agricultural systems to climate change by improving soil fertility and structure, soil water holding capacity and water and nutrients distribution through the soil profile, helping to prevent pests and diseases, and increasing yield stability. Indeed, the diversified cropping systems are more stable and resilient than monoculture systems. Crop diversification delivers a range of ecosystem services, contributes to improve crop productivity and resilience of farming systems and reduces GHG emissions from agricultural activities.

“Permanent soil organic cover” with crop residues and/or cover crops (e.g. legumes, cereals, or other crops planted between the main crops, primarily for the benefit of the soil rather than the crop yield) enables climate change adaptation by reducing soil erosion and degradation which can be exacerbated by the impact of extreme weather events (e.g. extreme precipitations, droughts and periods of soil saturation, extreme heat, strong wind events) and improving the stability of the conservation agriculture system. Indeed, cover crops improve soil properties (fertility and quality), help to manage soil erosion, preserve soil moisture, avoid compaction of the soil, contain pest and diseases, and increase biodiversity in the agro-ecosystem.

The three principles and related measures of conservation agriculture are applicable in all agricultural cropping systems but need to be adapted to the specific crop requirements and the local conditions of each agricultural region. Several European projects (e.g. SOLMACC, AgriAdapt, and HelpSoil) have been testing the effects of these measures on farms, promoting the application of techniques that help the achievement of adaptation and mitigation objectives.

IPCC categories

Structural and physical: Ecosystem-based adaptation options, Structural and physical: Technological options

Stakeholder participation

A successful implementation of conservation agriculture requires stakeholder participation from both public and private sectors and a strong collaboration between the various actors: farmers, farm advisory services (that provide farmers knowledge and skills to improve the applied agronomic techniques, crop productivity and farm income), researchers, policy makers, etc. Effective stakeholder-based participatory approaches are needed to ensure the dissemination and application of conservation agriculture practices and to refine the measures according to the specific characteristics of the agricultural systems considered, to obtain the highest possible effectiveness. Farmers and other stakeholders should be engaged in projects dealing with conservation agriculture practices, to acquire more awareness of the close link among agricultural practices, environmental impacts and socioeconomic effects, including the potential for adaptation to and mitigation of climate change.

Moreover, farmers should be guided during the initial period of conversion from traditional to conservation agriculture, to obtain all the required information and to gain experience with the new practices and be conscious of the labour and time needed for the transition to the new cultivation system. In this contest, the role of farm advisory services is essential, as well as the improvement of capacity building and education. The presentation of the effects of conservation agriculture techniques applied on real case studies could help the implementation of the measures and give indications to new farmers on which key practices generate success and what mistakes to avoid.

Success and Limiting Factors

Among the success factors for the implementation of conservation agriculture measures are: good stakeholder engagement, policies and government actions to promote and create favourable conditions for the application of conservation agriculture (such as free access to information), appropriate farm advisory services, public and private partnerships, and rewards for environmental services.

Some aspects can act as limiting factors for small farm dimensions, as for example for the implementation of practices that require investments in machinery (as for sod seeding in not tillage farming systems). In these cases, associations of farmers or collaboration with third parties are used to overcome this aspect. Other limiting factors include the inadequate dissemination of knowledge and good practices, the insufficient collaboration between researchers and farm advisory services and the lack of supports to farmers.

In some cases, there is still a farmer perception that tillage is necessary for soil improving, facilitating crop management and giving higher yields. Moreover, farmers are generally satisfied with the actual practices and do not feel an economic pressure to change, as clean and well-tilled fields are often associated with good farming practice. In this respect, the farm advisory services play a key role in encouraging the confidence of farmers new to conservation agriculture that the technology is working. This includes demonstrating the technology in other farmers' fields, demonstrating the economic benefits with facts and numbers and training people in the region to help others.

Costs and Benefits

The cost for implementing conservation agriculture measures is likely to vary between farms (depending on size and production system), geographical regions, and countries. However, it is reported by FAO that by not tilling the soil, farmers can save between 30% and 40% of time, labour and, in mechanized agriculture, fossil fuels as compared to conventional agriculture, reducing the associated costs. In general, conservation agriculture allows a reduction of the production costs and a reduction of time and labour (e.g. for land preparation and planting), and in mechanized systems it reduces the costs of investment and maintenance of machinery in the long term. Moreover, it allows yields comparable with modern intensive agriculture but in a sustainable way, allowing crop to better adapt to changed climatic condition respect to the ordinary farming management, in particular by reducing year-to-year yield variability. However, the positive effects on crop yields depend on the intensity and severity of climate change impacts.

The economic, agronomic and environmental benefits provided by conservation agriculture are detectable at global, regional, local and farm level. These benefits are also relevant in terms of adaptation to climate change, as through conservation agriculture crop yields are maintained or even improved, as well as in terms of mitigation, by increasing carbon sequestration and reducing greenhouse gases emissions.

Legal Aspects

The conservation agriculture practices should be supported by clear policies and procedures. The Common Agricultural Policy (CAP) of the European Union and the National and Regional Rural Programmes are among the major policy driving forces for the implementation of the conservation agriculture in the EU Member States.

The Common Agricultural Policy promotes the application of these practices through the “green direct payment” (or “greening”) (first pillar of the CAP) to support farmers who adopt or maintain farming practices (e.g. crop diversification) that help meet environmental and climate goals. Moreover, the second pillar of the CAP, the EU’s rural development policy, designed to support the rural areas, enables regional, national and local authorities to formulate their individual Rural Development Programmes and supports, among others, measures for sustainable management of natural resources and climate action, including the conservation agricultural practices. The second pillar programmes are co-financed by EU funds and regional or national funds.

Implementation Time

A year can be enough to implement the measures of conservation agriculture. The time required is highly dependent on knowledge dissemination, policies and government interventions, skills and funds availability, and stakeholders’ involvement.

Life Time

Conservation agriculture is a long-term adaptation measure and generally has a long lifetime (decades).

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